摘要
表面改性法制备了负载型双核金属甲氧基配合物催化剂Ni2 (OCH3 ) 2 /SiO2 ,采用IR和超临界反应技术对催化剂的表面结构、化学吸附性质和反应性能进行了研究。结果表明 ,Ni2 + 在Ni2 (OCH3 ) 2 /SiO2 中与载体SiO2 表面O2 -以双齿配位形式键合 ;CO2 在催化剂表面存在桥式吸附态和甲氧碳酸酯基物种 2种吸附态 ,丙烯则只有 1种分子吸附态 ;在超临界的条件下 ,CO2 和丙烯在Ni2 (OCH3 ) 2 /SiO2 催化剂上可以近 1 0 0 %选择性合成甲基丙烯酸 ;确定了Ni2 (OCH3 ) 2 /SiO2 催化丙烯与CO2 合成甲基丙烯酸的适宜反应条件为反应温度3 1 3K ,反应压力 7 5MPa,反应时间 3h。
The Ni 2(OCH 3) 2/SiO 2 catalyst was prepared by surface modification reaction and ion-exchange method. The surface structure, chemisorption and reactivity of the catalyst were examined by IR and supercritical reaction. The experiment results indicated that Ni 2+is bond with surface O 2- of SiO 2 support in bidentate fashion in the supported dinuclear bridged methoxide complex Ni 2(OCH 3) 2, that the CO 2 is chemically adsorbed on the catalysts in bridged adsorption state and carbonate species and the propylene is chemically adsorbed on the catalyst in a molecular adsorption state. Under supercritical condition 313 K, 7.5 MPa and reaction time 3 h, the Ni 2(OCH 3) 2/SiO 2 catalyst gave almost 100% methacrylic acid from CO 2 and propylene in synthesis.
出处
《应用化学》
CAS
CSCD
北大核心
2003年第11期1039-1043,共5页
Chinese Journal of Applied Chemistry
基金
国家重大基础研究前期研究专项 ( 2 0 0 1CCA0 3 60 0 )资助项目
关键词
甲基丙烯酸
CO2
丙烯
超临界反应
负载型催化剂
双核桥联配合物
methacrylic acid,carbon dioxide,propylene,supercritical reaction,supported catalyst,dinuclear bridged complex